TY - JOUR
T1 - Vertical oscillations of droplets in small droplet clusters
AU - Fedorets, Alexander A.
AU - Gabyshev, Dmitrii N.
AU - Shcherbakov, Dmitrii
AU - Bormashenko, Edward
AU - Dombrovsky, Leonid A.
AU - Nosonovsky, Michael
N1 - Publisher Copyright:
© 2021 Elsevier B.V.
PY - 2021/11/5
Y1 - 2021/11/5
N2 - Small clusters of condensed microdroplets can levitate above a heated water surface. Vertical oscillations of small clusters (one, two, and three droplets) in the frequency range below 90 Hz are studied and compared with recently reported horizontal oscillations. Two reproducible peak frequencies are at 41.6 ± 0.4 Hz and at 49.5 ± 0.2 Hz. These frequencies are much higher than those for horizontal oscillations (between 1.61 Hz and 5.96 Hz); however, corresponding amplitudes are much smaller, which suggests equal energy distributions between the degrees of freedom. The values of effective stiffness constants are obtained from the data on equilibrium height of levitation of droplets of different sizes, and possible sources of oscillations are discussed. The oscillations are caused by aerodynamic forces, and these are same forces which are responsible for the stability of the droplet cluster.
AB - Small clusters of condensed microdroplets can levitate above a heated water surface. Vertical oscillations of small clusters (one, two, and three droplets) in the frequency range below 90 Hz are studied and compared with recently reported horizontal oscillations. Two reproducible peak frequencies are at 41.6 ± 0.4 Hz and at 49.5 ± 0.2 Hz. These frequencies are much higher than those for horizontal oscillations (between 1.61 Hz and 5.96 Hz); however, corresponding amplitudes are much smaller, which suggests equal energy distributions between the degrees of freedom. The values of effective stiffness constants are obtained from the data on equilibrium height of levitation of droplets of different sizes, and possible sources of oscillations are discussed. The oscillations are caused by aerodynamic forces, and these are same forces which are responsible for the stability of the droplet cluster.
KW - Droplet cluster
KW - Droplet oscillations
KW - Gas flow instability
KW - Self-assembly
UR - http://www.scopus.com/inward/record.url?scp=85111940564&partnerID=8YFLogxK
U2 - 10.1016/j.colsurfa.2021.127271
DO - 10.1016/j.colsurfa.2021.127271
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AN - SCOPUS:85111940564
SN - 0927-7757
VL - 628
JO - Colloids and Surfaces A: Physicochemical and Engineering Aspects
JF - Colloids and Surfaces A: Physicochemical and Engineering Aspects
M1 - 127271
ER -